Tamper indicating closure with tear-off band

Abstract

 @ A tamper indicating closure for a finish of a container has an annular skirt (32) with an annular tamper indicating band (35) integrally attached thereto by a plurality of frangible bridges (38). The band (35) has a plurality of wedge-shaped tabs (40) that contact the container finish (22) and bend upwardly when the closure is applied to the container. When there is an attempt to remove the closure, the thicker portion (45) of each tab (40) wedge against the container finish (20) to apply torque to the band and break the bridges (38) to leave the tamper indicating band on the container.

Description

[0001] The present invention relates to a tamper or pilfer indicating closure with a tear-off band to indicate tampering before the ultimate user or consumer opens the closure and the container associated therewith.

[0002] Tamper indicating or so-called tamper resistant closures for finishes of containers have been disclosed, such closures having tear-off bands that are broken away from the main portion of the closure by frangible bridges when the closure is removed from the container.

[0003] Such closures for containers are disclosed in United States Patent Specification No.4,394,918; in United Kingdom Patent Specification Nos. 2,022,063; 1,265,008; 2,033,350; in German Patent Specification No. DE 30 25 751 Al; in French Patent Specifications No. 2,290,114; 2,241,812 and 2,490,598.

[0004] United States Patent Specification No.4,394,918, apparently more pertinent to the present invention than the others, discloses a screw cap for a finish of a container, the cap having a depending skirt with an annular tamper indicating band connected by frangible bridges 4 connected thereto. The band has a plurality of tabs or lock-lugs 7 that bend like fishhooks and contact the finish of the container just below a collar 13 of the container neck. The lock-lugs contact the container finish so that when the screw cap is turned for removal, shearing forces cause the bridges 4 to break and leave the band on the container, the lock-lugs 7 being able to resist compression and shearing forces. When first moulded, the lock-lugs 7 are said to be inclined downwardly from the band at an angled of about 120° to 140° and when the cap is screwed on the container, the lugs bend to define an acute angle/9 of, for instance, 40° to 60°.

[0005] According to one aspect of the present invention a closure for a finish of a container having a neck ring, comprises a cap and an annular tamper-indicating or so-called tamper resistant band member connected to the bottom of the cap with a series of frangible break-away bridges that attach the tamper indicating band member to the cap, the member comprising an annular band integral with the bridges and a lower glass-finish contacting member that bends upwardly like a fishhook when the cap is applied to the finish, characterised in that the glass-finish contacting member is wedge shaped and the end portion of the contacting member remote from the annular band is wider and thicker than the portion nearer the band for greater contact of the end portion against the neck ring of the glass finish.

[0006] According to another aspect of the present invention there is provided a closure in combination with a container having a finish with a neck ring including an annular finish bead, the closure comprising a cap and a tamper-indicating or so-called tamper resistant member connected to the cap with a series of frangible break-away bridges that attach the tamper resistant member to the cap, the tamper indicating member comprising an annular band integral with the bridges, and a plurality of glass finish contacting flanges that bend upwardly like a fishhook when the cap is applied to the finish, the flanges initially contacting the glass container finish above the annular bead, characterised in that the flanges are wedge-shaped, there being interference between the bead and the flanges when the cap is loosened whereby torque is applied to the bridges by contact of the wedge-shaped flanges with the container finish, there being then an angle of about 45° to 90° between the horizontal and the upper part of the flange.

[0007] Preferably the glass contacting member takes the form of a plurality of circumferntlally disposed gripping tabs or flanges which are so constructed and arranged that they bend like fishhooks when the closure is applied and provide more contact against the neck finish of a container and more torque against the bridges when the closure is removed whereby the bridges break and the band is left around the neck of the container clearly indicating a closure removal or removal attempt.

[0008] The invention will be further described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a side elevational perspective view of a cap with its tamper indicating band provided with tabs, according to one embodiment of the present invention,

Figure 2 is a bottom plan view of the cap of Figure 1,

Figure 3 is an enlarged sectional view of the lower skirt, annular band and depending tabs of the closure of Figure 1 being applied, in the initial stage, to a finish of a container,

Figure 4 is an enlarged sectional view of the cap and container of Figure 3, the cap being applied a little farther down the container finish,

Figure 5 shows the cap and closure of Figure 4 with the cap being in or nearly in its tightened position, and

Figure 6 shows the cap and container of Figure 3 with the cap in its final tightened position with the tabs bent like fishhooks contacting the container finish, the bridges being broken to show the band as a tamper indicating band.

[0009] The present invention provides a tamper indicating closure for a finish of a container, the closure having a depending skirt portion and, connected thereto by frangible bridges, an annular tamper indicating band provided with wedge-shaped tabs that bend upwardly like fishhooks when the closure is put on and which wedge against the finish to apply torque that breaks the bridges when the closure is removed.

[0010] As seen in the drawings, there is provided a closure 1 in combination with a container 10 having a finish 15 with a neck ring 20 including an annular finish bead 22. The closure or cap 1 has a top 30 with a main depending skirt portion 32. There is provided cap skirt threads 33 and a top cap sealing ring 34. A tamper resistant band member 35 is connected to the cap skirt 32 with a series of frangible bridges 38 that are designed to break when the closure is removed or partly opened in an attempt to remove the same. The break-away band member 35 has integrally connected therewith a plurality of wedge-shaped glass-contacting tabs or flanges 40 that bend like fishhooks when the closure is tightened on the container. The outer wedge portion 45, that is to say, the portion remote from the band member 35, is larger, being wider and generally thicker, than the rest of the tab 40 including the portion 48 next to the band member 35. The outer tab portion, as the closure is in process of being applied to the container, contacts and wedges against the finish 15 above the annular bead 22 as illustrated in Figures 3 and 4. When attempting to remove the closure from its fully applied position as illustrated in Figure 5, there is interference between the container bead and tabs 40 whereby torque is applied to the band 35 and bridges 38 resulting in breaking the bridges as illustrated in Figure 6, thereby indicating that the closure has been loosened enough to break the bridges and have the tamper indicating band 35 remain on the container.

[0011] As seen in the drawings, the outer portion 45 of the tab 40 is generally 1-¹/4 to 2 or 3 times as wide and as thick as the thinner portion 48. Preferably the width of the wide portion 45 is about 1.8 to 2.2 times the width of the thinner portion 48.

[0012] As shown in Figure 2, the tabs depend from the skirt periphery. The angled subtended by one of the tabs is from about 10° to 360° depending on the size and design of the cap. With a small cap

would be

greater than about 20° and, with a large cap,, would be about 10° or more.

[0013] The annular band is to function as an annular ring carrying at its outer periphery stiff tab members orientated inwardly and upwardly on a rigid plastic closure. The purpose of the band and tabs is to overcome the tensile strength of frangible break-away bridges which join a tamper resistant member to its closure. The annular band will function properly when generally the tabs are oriented within an upward angle between 45° and 90° from the horizontal as long as contact with the lower glass finish bead is made. The upward angles , is shown in Figure 6. It is also advantageous to limit the neck of the container to a diameter which will be approximately the internal diameter of the annular band when the tab or tabs are at the 45° position. This will assure that the vertical forces on the bridges will be equal to or greater than the horizontal forces.

[0014] With a condition where the rigid annular band is at 45°, vertical forces (Fy) and horizontal forces (F_H) are in equilibrium. The vector forces Fy and F_H are shown in Figure 6. Since the cross sectional area of the annular band is many times greater (say, 10 to 100 times or more) than that of the frangible break-away bridges, deformation or breakage of the bridges will occur as the closure is removed from its container. Also, the tensile strength of the bridges is smaller than the compressive strength of the annular band when a comparison of cross sections is made.

[0015] Angles between 45° and 90° from the horizontal for the upwardly oriented tabs will take the forces out of equilibrium. The greater the angle becomes, the greater the vertical forces become, thus making the vertical forces over-ride the horizontal forces until there are little or no more horizontal forces.

[0016] Assuming the annular band and the tabs to be 89 or 90° from the horizontal and with slight interference between the glass finish bead and the annular band, vertical forces overcome the tensile strength of the bridges causing the bridges to break away upon cap removal from its container.

[0017] The most ideal angle for the upwardly bent tabs of the annular band is found to be between 60° and 75° from the horizontal since this will ensure contact between the annular band and tabs and the glass finish bead, and a substantial vertical force to maximize the condition to break the frangible bridges adjoining the tamper indicating member to its closure.

[0018] The preferred cap construction has about 6 to 10 tabs and preferably about 8. The length of each tab is generally about ³/4 to 1-¹/2 times the width of the annular band. The width of the wide portion 45 of the tab is generally about 1.5 to 2.5 times and preferably about twice the width of the thin portion 48, but the width of portion 45 is only about ¹/8 to ¹/3 that of the width of the annular band. The thickness of the portion 45 is generally about ³/4 to ⁹/10 of the thickness of the annular band. As seen in the drawings, the width and thickness of the frangible bridges are much less than the thinner portion 48 of the tab.

Claims

1. A closure for a finish of a container having a neck ring, the closure comprising a cap and an annular tamper-indicating or so-called tamper resistant band member connected to the bottom of the cap with a series of frangible break-away bridges that attach the tamper indicating band member to the cap, the member comprising an annular band integral with the bridges and a lower glass-finish contacting member that bends upwardly like a fishhook when the cap is applied to the finish, characterised in that the glass-finish contacting member is wedge shaped and the end portion of the contacting member remote from the annular band is wider and thicker than the portion nearer the band for greater contact of the end portion against the neck ring of the glass finish.

2. A closure according to claim 1, characterised in that the glass contacting member is an annular flange moulded at a downward angle to the band and adapted to bend upwardly and behind the skirt of the cap to contact a lower bead of the glass finish to provide means for the member to grasp the bead and glass finish even when the bridges are broken to indicate the closure has been tampered with.

3. A closure according to claim 1, characterised in that the glass contacting member is a plurality of circumferentially disposed gripping tabs moulded at an angle to the band, the tabs bending upwardly around a bead on the glass finish when the closure is secured on the container, each tab end portion remote from the annular band member contacting the underside of the neck ring of the glass finish and holding the band and tabs on the glass finish even when the bridges are broken.

4. A closure according to claim 1, in which the glass finish contacting member is bent upwardly at angle of about 5° to 85° with the horizontal when the cap is applied to the container.

5. A closure according to claim 1, characterised in that the end portion of each wedge-shaped glass-finish contacting member is about 1-¹/2 to 4 times the width of that portion of the member which is connected to the annular band.

6. A closure according to claim 3, characterised in that each of the tabs has a relatively thin portion near the band, the tab tapering gradually from a relatively thicker and wider contacting end portion.

7. A closure according to claim 1, characterised in that the glass-finish contacting portion of the glass-finish contacting member is wider and thicker than the middle portion of the wedge-shaped glass-finish contacting member.

8. A closure according to claim 3, characterised in that the width of the glass-finish contacting portion of each tab is about ¹/8 to ¹/3 the length of the tab.

9. A closure according.to claim 3, characterised in that the bridges are made by an annular score line at the bottom of the cap.

10. A closure in combination with a container having a finish with a neck ring including an annular finish bead, the closure comprising a cap and a tamper-indicating or so-called tamper resistant member connected to the cap with a series of frangible break-away bridges that attach the tamper resistant member to the cap, the tamper indicating member comprising an annular band integral with the bridges, and a plurality of glass finish contacting flanges that bend upwardly like a fishhook when the cap is applied to the finish, the flanges initially contacting the glass container finish above the annular bead, characterised in that the flanges are wedge-shaped, there being interference between the bead and the flanges when the cap is loosened whereby torque is applied to the bridges by contact of the wedge-shaped flanges with the container finish, there being then an angle of about 45° to 90° between the horizontal and the upper part of the flange.

11. A closure in combination with a container according to claim 10, characterised in that the angle between the horizontal and the flange is about 60 to 75°.

12. A closure in combination with a container according to claim 10, characterised in that the widest part of a tab at the closure periphery subtends an angle from about 10° to 360° at the centre line of the closure.

13. A closure according to claim 12, characterised in that said subtended angle is at least about 20°.

14. A closure according to claim 3, characterised in that the bridges are made by moulding at the bottom of the cap.

Drawing